Wind power generation system including a rotating pedestal and a wind power generation apparatus with a duct

ABSTRACT

Provided is a wind power generation system including: a wind power generation apparatus that includes at least a duct having a longitudinal cross section formed in a substantial streamline shape, the longitudinal cross section being cut along a central axis, an impeller placed in the duct, and a power generator that generates power by rotation of the impeller; an anemovane installed so as to be able to measure a wind direction and/or wind power in a vicinity of the wind power generation apparatus; a rotating pedestal that supports the wind power generation apparatus so as to be rotatable along a supporting surface; and a control device that controls a rotational angle of the rotating pedestal based on the wind direction and/or the wind power measured by the anemovane.

TECHNICAL FIELD

The present invention relates to a wind power generation system.

BACKGROUND ART

Recently, from consideration for global environment, concern about powergeneration apparatuses utilizing clean energy has been growing. As oneof such power generation apparatuses, a wind power generation apparatusis proposed. The wind power generation apparatus is an apparatus thatrotates an impeller by wind power, and converts rotational energyobtained by the rotation of the impeller into electric energy.

It is said that a power generation amount of the wind power generationapparatus is proportional to the cube of wind velocity, and in order toimprove the power generation amount and power generating efficiency,various studies are performed. For example, Patent Literature 1discloses that a cross section of a duct provided around an impeller isformed in a streamline shape from a front end to a rear end of the duct,so that the velocity of wind flowing into the duct from a front surfaceside of the duct is increased, and an power generation amount isimproved.

For example, Patent Literature 2 discloses that a position of animpeller in a duct having a streamline shaped cross section is devised,Patent Literature 3 discloses that a ratio between each of the openingdiameter (intake port diameter) of a front end of a duct and the openingdiameter (exhaust port diameter) of a rear end, and the inner diameterof the duct is devised. For example, Patent Literature 4 discloses anaggregate of wind power generation apparatuses including a plurality ofwind power generation apparatuses, such ones as disclosed in PatentLiterature 1. According to Patent Literature 4, a support that supportsthe aggregate is provided through a bearing so as to be rotatable to theearth's surface, and the support is rotated by wind power received by anouter peripheral surface of the duct, so that the wind power generationapparatuses turn in the direction from which wind blows.

CITATION LIST Patent Literature

Patent Literature 1: JP 2003-028043 A

Patent Literature 2: JP 2007-309287 A

Patent Literature 3: JP 2007-327371 A

Patent Literature 4: JP 2003-097416 A

SUMMARY OF INVENTION Technical Problem

However, wind power generation apparatuses disclosed in PatentLiteratures 1 to 3 have a problem in that as long as wind does not enterfrom just a front side of an intake port, air turbulence is generated inthe duct by wind which collides with an inner wall of the duct, and awind velocity increasing effect cannot be obtained as expected.Particularly, in a case in which wind blows from just a lateral side ofthe duct, wind that enters the duct is weak, and therefore there is aproblem in that the power generation amount or power generatingefficiency is greatly lowered.

The aggregate of the wind power generation apparatuses disclosed inPatent Literature 4 is designed such that the intake ports of the windpower generation apparatuses can be turned in the direction from whichwind blows. This is only for changing the direction of the intake portsby utilizing wind power received by the outer peripheral surface of theduct, the direction of the intake ports cannot be controlled with highprecision, and a certain amount of dislocation is generated between thedirection from which wind blows, and the direction of the intake port ofeach wind power generation apparatus. As a result, similarly to PatentLiteratures 1 to 3, air turbulence is generated in the duct by windwhich collides with the inner wall of the duct, and a wind velocityincreasing effect cannot be obtained as expected. Recently, clean energyattracts attention, and appearance of a wind power generation apparatushaving a further improved power generation amount and power generatingefficiency has been desired.

The present invention has been made in view of the aforementionedproblems. Accordingly, an object of the present invention is to providea wind power generation system including a wind power generationapparatus having an impeller in a duct, the wind power generation systembeing capable of reducing generation of air turbulence in the duct,sufficiently increasing the velocity of wind in the duct, and improvinga power generation amount and power generating efficiency.

Solution to Problem

The above objects can be achieved by a wind power generation systemdescribed below.

[1] A wind power generation system comprising: a wind power generationapparatus that includes at least a duct having a longitudinal crosssection formed in a substantial streamline shape, the longitudinal crosssection being cut along a central axis, an impeller placed in the duct,and a power generator that generates power by rotation of the impeller;an anemovane installed so as to be able to measure a wind directionand/or wind power in a vicinity of the wind power generation apparatus;a rotating pedestal that supports the wind power generation apparatus soas to be rotatable along a supporting surface; and a control device thatcontrols a rotational angle of the rotating pedestal based on the winddirection and/or the wind power measured by the anemovane.

[2] The wind power generation system according to above [1], wherein thecontrol device further controls rotational speed of the rotatingpedestal based on the wind power measured by the anemovane.

[3] The wind power generation system according to above [1] or [2],wherein at least a portion of an inner wall of the duct expands towardthe central axis of the duct to form a minimum inner diameter part atwhich an inner diameter of the duct is minimum between an intake portand an exhaust port of the duct.

[4] The wind power generation system according to above [3], wherein theimpeller is placed between the minimum inner diameter part and theexhaust port of the duct, and a distance from the minimum inner diameterpart to the impeller is in a range of 19.8 to 29.0% of a distance fromthe minimum inner diameter part to the exhaust port.

[5] The wind power generation system according to any one of above [1]to [4], wherein a support for supporting the impeller and the powergenerator is erected from the inner wall of the duct toward a center ofgravity of the duct or a vicinity of the center of gravity.

[6] The wind power generation system according to any one of above [1]to [5], wherein the impeller has four blades.

Advantageous Effects of Invention

According to the wind power generation system according to the presentinvention, the rotational angle of the rotating pedestal that supportsthe wind power generation apparatus so as to be rotatable is controlledbased on the wind direction and/or the wind power measured by theanemovane, so that it is possible to reduce generation of air turbulencein the duct of the wind power generation apparatus, sufficientlyincrease the velocity of wind in the duct, and improve a powergeneration amount and power generating efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view illustrating an example of a configuration of awind power generation apparatus according to an embodiment of thepresent invention.

FIG. 2 is a partial sectional view illustrating an example of theconfiguration of the wind power generation apparatus in a case in whicha duct 11 is cut along a line X-X illustrated in FIG. 1.

FIG. 3 is a partial sectional view illustrating an example of aconfiguration of a wind power generation apparatus according to anembodiment of the present invention.

FIG. 4 are schematic views illustrating an example of a configuration ofthe rotating pedestal according to an embodiment of the presentinvention.

FIG. 5 is a sectional view of the rotating pedestal in a case in whichthe rotating pedestal is cut along a line Y-Y illustrated in FIG. 4.

FIG. 6 is a flowchart illustrating an example of a control process ofthe rotating pedestal according to an embodiment of the presentinvention.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the drawings, but the present invention is not limited tothe drawings and the embodiments. The present invention is not limitedto the following preferable numerical values and configurations.

In this specification, a “substantial streamline shape” means such ashape that a shape of an inner peripheral side edge in a longitudinalcross section of a wall body of a duct is deformed within a range of thepurpose of increasing the velocity of wind which flows into the ductfrom an intake port side of the duct without causing turbulence insidethe duct. Additionally, the “substantial streamline shape” includes sucha shape that a shape of an outer peripheral side edge in thelongitudinal cross section of the wall body of the duct is deformedwithin a range of the purpose of preventing generation of a swirl on anouter peripheral surface. An example of such a deformation includes acase in which the shape of a portion of the outer peripheral side edgewhich reaches a rear end from a front end of the duct in thelongitudinal cross section of the wall body of the duct is formed in thestreamline shape. Additionally, the “substantial streamline shape”includes such a shape that the shape of the outer peripheral side edgein the longitudinal cross section of the wall body of the duct islinear.

[Wind Power Generation Apparatus]

Hereinafter, a wind power generation apparatus will be described. FIG. 1is a front view illustrating an example of a configuration of a windpower generation apparatus according to an embodiment of the presentinvention. FIG. 2 is a partial sectional view illustrating an example ofthe configuration of the wind power generation apparatus in a case inwhich a duct 11 is cut along a line X-X illustrated in FIG. 1. The windpower generation apparatus 10 illustrated in FIG. 1 and FIG. 2 includesat least the cylindrical duct 11, a cylindrical container 30, a currentcollection cable 35, a support 40, a support plate 41, and four legparts 42.

The duct 11 includes at least a front end 12 forming an intake port, aminimum inner diameter part 13 at which the inner diameter of the duct11 is minimum, a rear end 14 forming an exhaust port, and a cable hole15 for allowing a current collection cable 35 connected to a powergenerator 34 to pass through. The duct 11 includes an outer diameter D1of the intake port side of the duct 11. The inner diameter of the duct11 gradually reduces its length from the front end 11 to the minimuminner diameter part 13, and gradually increases from the minimum innerdiameter part 13 to the rear end 14. In other words, one portion of aninner wall body of the duct 11 expands toward a central axis 19 of theduct, and the minimum inner diameter part at which the inner diameter ofthe duct is minimum is formed between the intake port and the exhaustport. Thus, the duct 11 is configured such that a shape of alongitudinal cross section cut by the line X-X along the central axis 19is formed in a substantial streamline shape, so that it is possible toincrease the velocity of wind that flows into the duct from the intakeport of the duct 11, and it is possible to improve a power generationamount and power generating efficiency.

A ratio of the length of the intake port diameter Di of the duct 11 tothe length of the inner diameter Dm of the minimum inner diameter partof the duct 11 (Di/Dm) is, for example, preferably in a range of 1.4 to2.6, more preferably in a range of 1.8 to 2.3, and much more preferablyin a range of 1.9 to 2.1. When a value of Di/Dm is less than 1.4, thereis a possibility that the velocity of the wind that flows into the duct11 is not sufficiently increased in a region from the front end 12 tothe minimum inner diameter part 13. On the other hand, when the value ofDi/Dm exceeds 2.6, resistance to wind in the front end 12 and in thevicinity of the front end 12 is increased, and therefore one portion ofwind that blows toward the intake port flows outside the duct 11, andthe quantity of wind that flows in the duct 11 is reduced. As a result,there is a possibility that power generating efficiency is lowered.

A ratio of the length of the exhaust port diameter De of the duct 11 tothe length of the inner diameter Dm of the minimum inner diameter partof the duct 11 (De/Dm) is, for example, preferably in a range of 1.1 to1.6, more preferably in a range of 1.2 to 1.5, and much more preferablyin a range of 1.3 to 1.4. When a value of De/Dm is less than 1.1,atmospheric pressure on the rear side of the minimum inner diameter part13 tends to increase, and the quantity of wind that flows into the duct11 from the intake port tends to reduce. On the other hand, when thevalue of De/Dm exceeds 1.6, wind that flows from the minimum innerdiameter part 13 to the rear end 14 peels from an inner peripheral sidesurface of the duct 11, so that turbulence tends to be likely to occurin a flow of wind. As a result, there is a possibility of causing aproblem in that the velocity of wind in the vicinity of the impeller 31is reduced, the power generation amount or the power generatingefficiency is lowered, or output power becomes unstable, for example.

When turbulence of the flow of wind that passes through the impeller iscaused by a slipstream that is generated behind the duct 11, thecylindrical container 30, or the support 40, or a Karman vortex causedby peeling of wind from a duct inner surface, a cylindrical containersurface, or a support surface, a velocity component of the directionother than a velocity component of the travelling direction is generatedin the wind, and the flow of the wind sometimes becomes slow behind theimpeller in the duct. In a case in which such wind turbulence occurs,even when the cross section shape of the duct is formed in thesubstantial streamline shape, the velocity of wind that flows into theduct 11 from the intake port cannot be sufficiently increased, and thereis a possibility that higher power generating efficiency is not obtainedas expected. Accordingly, influence on the power generating efficiencyby such wind turbulence is preferably reduced as much as possible.

From a viewpoint of reduction of the influence on the power generatingefficiency by the turbulence of the wind that is generated in the duct11, the length L1 in the central axis direction of the duct 11 is, forexample, preferably 1.3 to 3.0 times of the intake port diameter Di ofthe intake port formed by the front end 12, more preferably 2.5 to 3.0times, and much more preferably 2.8 to 3.0 times. With such aconfiguration, a position at which turbulence behind the impeller occursis shifted to a sufficient rear side with respect to a position at whichthe impeller is installed, and influence on a wind velocity increasingeffect in the vicinity of the impeller can be reduced. Accordingly, thevelocity of the wind that flows into the duct 11 from the intake portcan be sufficiently increased until the wind reaches the impeller, andtherefore it is possible to suppress lowering of the power generatingefficiency.

Similarly, from the viewpoint of reduction of the influence on the powergenerating efficiency by the turbulence of the wind that is generated inthe duct 11, the duct 11 is preferably configured such that both theouter peripheral side edge and the inner peripheral side edge of theduct 11 do not intersect with a straight line connecting the front end12 and the rear end 14 in the longitudinal cross section of the duct 11.When swirl is generated on an outer peripheral surface of the duct 11,the generated swirl sometimes moves behind the duct 11 (behind theimpeller). Accordingly, in order to prevent the generation of the swirlon the outer peripheral surface, the shape of the outer peripheral sideedge in the longitudinal cross section of the duct 11 is, much morepreferably, formed in the substantial streamline shape.

The cylindrical container 30 includes at least the impeller 31, arotating shaft 33, and the power generator 34. The cylindrical container30 is preferably formed in a conical shape or a conical shape having anexpanded side surface (so-called cone shape). With such a configuration,it is possible to enhance the wind velocity increasing effect of wind bynot only the inner wall of the duct 11 but also the cylindricalcontainer. As a result, it is possible to enhance the power generationamount and the power generating efficiency.

The impeller 31 is provided on a rear side of the cylindrical container30, includes blades 32, and is connected to the rotating shaft 33. Therotating shaft 33 is provided in the cylindrical container 30 along thecentral axis 19 of the duct 11, and is connected to the impeller 31 andthe power generator 34. The power generator 34 is provided in thecylindrical container 30, and is connected to the rotating shaft 33 andthe current collection cable 35. The blades 32 receive power of wind, sothat the impeller 31 rotates, the rotational energy is transmitted tothe power generator 34 through the rotating shaft 33, and is convertedinto electric energy in the power generator 34. Electric energy obtainedby the power generator 34 is transmitted to a power source apparatus,and an external current collector of a rotating pedestal 50 describedbelow through the current collection cable 35.

The impeller 31 (blades 32) is preferably placed between the minimuminner diameter part 13 and the exhaust port. A distance L3 from theminimum inner diameter part 13 to the impeller 31 is preferably in arange of 19.8 to 29.0% of a distance L2 from the minimum inner diameterpart 13 to the exhaust port, more preferably in a range of 21 to 25%,and much more preferably in a range of 22 to 23%. The wind that flowsinto the duct 11 has a point at which the wind velocity is maximizedbetween the minimum inner diameter part 13 and the exhaust port.Accordingly, the impeller 31 is placed between the minimum innerdiameter part 13 and the exhaust port, particularly, the impeller 31 isplaced such that the distance from the minimum inner diameter part 13 tothe impeller 31 is in a range of 19.8 to 29.0% of the distance from theminimum inner diameter part 13 to the exhaust port, so that wind whosewind velocity is increased up to a maximum or a state near to themaximum can be given to the blades 32. As a result, the power generationamount and the power generating efficiency tend to be able to beimproved.

The number of the blades 32 to be provided in the impeller 31 is notparticularly limited, but is preferably, for example, 4 to 5. When thenumber of the blades 32 is 3 or less, quantity of wind received by theblades 32 is small, and power generating efficiency is lowered. When thenumber of the blades 32 exceeds 5 or more, swirls generated from theblades 32 are increased, and the power generating efficiency is lowered,and noise caused by rotation of the blades 32 becomes loud.Additionally, the number of the blades 32 is particularly preferably 4.In a case in which the number of the blades 32 is 4, a wind powergeneration apparatus, noise of which is not too loud, and powergenerating efficiency of which is high, can be obtained. Additionally,in a case in which the number of the blades 32 is 4, it is possible tofacilitate balance adjustment of the blades 32 at the time ofmanufacturing, and control manufacturing cost compared to a case inwhich the number of the blades 32 is five.

The support 40 is erected on the inner wall of the duct 11 so as tosupport the cylindrical container 30. In this embodiment, the foursupports 40 are provided, and the current collection cable 35 from thepower generator 34 toward the cable hole 15 is buried in one of thesupports. The support 40 is preferably erected from the inner wall ofthe duct 11 toward the center of gravity of the duct 11 or the vicinityof the center of gravity of the duct. With such a configuration, it ispossible to smoothly and promptly perform rotating operation by therotating pedestal 50 described below.

A distance L4 from the minimum inner diameter part 13 to the supports 40is preferably 10% or more of the length of the distance L2 from theminimum inner diameter part 13 of the duct to the rear end 14, morepreferably 20% or more of the length of the distance L2, and much morepreferably 23% or more of the length of the distance L2. With such aconfiguration, the support 40, which is likely to prevent increase ofthe velocity of wind that flows into the duct 11, is placed at aposition apart from the minimum inner diameter part 13, and therefore itis possible to sufficiently enhance the wind velocity increasing effectof wind in a region between the intake port of the duct 11 and theminimum inner diameter part 13.

The support plate 41 is a plate for supporting the duct 11, and theshape and the material of the support plate is not limited as long asthe support plate can support the duct 11. The leg parts 42 are provideddownward from the support plate 41, and are fixed to fixing parts 52 ofthe rotating pedestal 50 described below.

FIG. 3 is a partial sectional view illustrating an example of aconfiguration of a wind power generation apparatus according to anembodiment of the present invention. The wind power generation apparatusillustrated in FIG. 3 is a modification of the wind power generationapparatus illustrated in the above FIG. 1 and FIG. 2, and thedescription about the portions denoted by reference numerals identicalto those of the wind power generation apparatus of FIG. 1 and FIG. 2will be appropriately omitted. The contents described as description ofthe wind power generation apparatus of FIG. 1 and FIG. 2 can adopt tothe wind power generation apparatus of FIG. 3 in a range in whichinconsistency is not caused. The following description related to thewind power generation apparatus of FIG. 3 can also adopt to the windpower generation apparatus of FIG. 1 and FIG. 2 in a range in whichinconsistency is not caused.

The outer peripheral side edge of the duct 11 has such a shape as togradually approach the central axis 19 after gradually separating fromthe central axis 19, from the intake port side to the exhaust port side,in the longitudinal cross section of the duct 11. In other words, theouter peripheral side edge of the duct 11 has the substantial streamlineshape. With such a configuration, it is possible to sufficientlysuppress generation of a swirl on the outer peripheral surface. As aresult, it is possible to suppress lowering of the wind velocityincreasing effect of the wind in the duct 11.

The outer peripheral side edge of the duct 11 includes a wind directionadjuster 16 on a rear side (exhaust port side) thereof. The winddirection adjuster 16 includes a skirt part 17 integrally formed withthe duct 11, and composed of an inclined plane formed so as to separatefrom the central axis 19 toward the rear side of the duct, an edge 18connected to the skirt part 17, and having a surface formed so as toseparate from the central axis 19, and substantially perpendicular tothe central axis 19.

The wind direction adjuster 16 gradually adjusts the direction of windthat travels toward the rear side along an outer surface of the duct 11,to the direction toward the radially outside of the duct 11 by the skirtpart 17, and then drastically adjusts the direction of the wind towardthe radially outside of the duct 11 by the edge 18. With such aconfiguration, a space region (hereinafter also referred to as a“decompression region”) in which the atmospheric pressure is low can beformed behind the edge 18. As a result, larger quantity of wind isfurther allowed to flow from the intake port of the duct 11, and it ispossible to enhance the wind velocity increasing effect.

The length L5 along the central axis 19 direction in the wind directionadjuster 16 is preferably in a range of 5 to 25% of the length L1 in thecentral axis 19 direction of the duct 11, more preferably in a range of5 to 20%, and much more preferably in a range of 5 to 18%. In a case inwhich the length L5 is less than 5% of the length L1, there is apossibility that the decompression region cannot be sufficientlygenerated. On the other hand, in a case in which the length L5 exceeds25% of the length L1, the size of the wind direction adjuster 16 becomestoo large. As a result, handling of the wind power generation apparatus10 tends to become difficult.

A ratio of the length of the maximum outer diameter D2 of the exhaustport side of the duct 11 to the length of the intake port diameter Di ofthe duct 11 (D2/Di) is preferably, for example, in a range of 110% to140%, more preferably in a range of 115% to 135%, and much morepreferably in a range of 120% to 130%. When a value of D2/Di is lessthan 110%, there is a possibility that the decompression region cannotbe sufficiently generated. On the other hand, in a case in which thevalue of D2/Di exceeds 140%, the size of the wind direction adjuster 16becomes too large compared to the size of the exhaust port. As a result,handling of the wind power generation apparatus 10 tends to becomedifficult.

The impeller 31 is provided so as to be located on the intake port sidewith respect to the support 40. With such a configuration, turbulence ofthe flow of wind generated by the support 40 can be generated at aposition sufficiently apart from the impeller 31, and therefore it ispossible to suppress lowering of the wind velocity increasing effect inthe vicinity of the impeller 31.

[Rotating Pedestal]

Hereinafter, the rotating pedestal will be described. The rotatingpedestal is a part that supports the wind power generation apparatusaforementioned so as to be rotatable. The rotating pedestal has afunction of controlling its own rotational angle such that the directionof the intake port of the wind power generation apparatus is directed inthe direction from which wind blows, based on the wind direction and/orwind power measured by an anemovane.

FIG. 4 are schematic views illustrating an example of a configuration ofthe rotating pedestal according to an embodiment of the presentinvention. FIG. 4(a) is a top view illustrating an example of aconfiguration of the rotating pedestal according to an embodiment of thepresent invention, and FIG. 4(b) is a front view of the rotatingpedestal illustrated in FIG. (a). FIG. 5 is a sectional view of therotating pedestal 50 in a case in which the rotating pedestal 50 is cutalong a line Y-Y illustrated in FIG. 4(a).

The rotating pedestal 50 having a substantially columnar shapeillustrated in FIG. 4 and FIG. 5 includes at least a rotating part 51including the four fixing parts 52 on an upper surface thereof, a basepart 54 that supports the rotating part 51, a control device 55 thatcontrols rotation of the rotating pedestal 50, and a ball bearing 56provided between the rotating part 51 and the base part 54 such that therotating part 51 is rotatable. A cable hole 53 is provided at a centralposition on the top view of the rotating pedestal 50 so as to penetratethe rotating part 51 and the base part 54. The control device 55 isconnected to an anemovane 61 installed so as to be able to measure thewind direction and the wind power (wind velocity) in the vicinity of thewind power generation apparatus 10 through a cable 62. The controldevice 55 and the anemovane 61 may be configured to be connected byradio without providing the cable 62.

As long as the rotating pedestal 50 can rotatably support the wind powergeneration apparatus 10, and has a function of controlling its ownrotational angle such that the direction of the intake port of the windpower generation apparatus 10 is directed in the direction from whichwind blows, based on the wind direction and/or the wind power measuredby the anemovane 61, the shape, the material, the configuration, and thelike of the rotating pedestal 50 are not particularly limited.

The fixing parts 52 are provided to fix the leg parts 42 of the windpower generation apparatus 10. The cable hole 53 is provided to allowthe current collection cable 35 extending from the wind power generationapparatus 10 to pass through. The ball bearing 56 is provided in orderto suppress abrasion or heat generation caused between the rotating part51 and the base part 54 by rotation of the rotating part 51. In place ofthe ball bearing 56, a known bearing such as a roller bearing, a taperroller bearing, and a needle bearing may be used.

The control device 55 is provided in the rotating pedestal 50. However,as long as the control device can rotate the rotating part 51, aninstallation position of the control device is not limited. The controldevice 55 includes at least a rotational angle detection sensor, anorigin position detection sensor, a control circuit, a motor forrotation, a power supply circuit, and a battery.

The rotational angle detection sensor has a function of detecting therotational angle of the rotating part 51, and inputting the detectedrotational angle as an output signal to the control circuit. Thedetection of the rotational angle by the rotational angle detectionsensor is preferably performed, for example, with precision of ±3degrees, more preferably performed with precision of ±2 degrees, andmuch more preferably performed with precision of ±1 degree. The originposition detection sensor has a function of setting an origin position(direction based on the rotating part 51) of the rotating part 51, anddetecting that the rotating part 51 passes through the origin position.The control circuit calculates the direction in which the rotating part51 (intake port of the wind power generation apparatus 10) is currentlydirected, by the rotational angle detected by the rotational angledetection sensor, and the origin position set by the origin positiondetection sensor.

The control circuit controls the rotational angle of the rotating part51 based on the information related to the wind direction and/or thewind power measured by the anemovane 61. The control circuit preferablycontrols the rotational speed of the rotating part 51 based on theinformation related to the wind direction and/or the wind power measuredby the anemovane 61. A control process by the control circuit will bedescribed in detail in description of FIG. 6.

The motor for rotation has a function of rotating the rotating part 51based on an output signal from the control circuit. The power supplycircuit and the battery each have a function of supplying power fordriving the control device 55. The power supply circuit and the batteryare preferably configured so that the power supply circuit and thebattery can store electric power generated by the wind power generationapparatus 10 through the current collection cable 35.

As long as the anemovane 61 can measure the wind direction and/or thewind power (wind velocity), and transmit information related to themeasured wind direction and/or wind power (wind velocity) to the controldevice 55 through a cable or by radio, the anemovane 61 is notparticularly limited, and a conventionally known anemovane can beappropriately used. The anemovane 61 preferably can measure both thewind direction and the wind power, and transmit the information relatedto both the measured wind direction and wind power to the control device55 through a cable or by radio. As long as a position at which theanemovane 61 is installed is a position at which the wind directionand/or the wind power in the vicinity of the wind power generationapparatus 10 can be measured, the position is not particularly limited.Here, the vicinity of the wind power generation apparatus 10 ispreferably, for example, a position within a radius of 3 m from theintake port of the wind power generation apparatus 10, and morepreferably a position within a radius of 2 m.

The wind power generation system of the present invention may be theaggregate of the wind power generation system composed of a plurality ofthe wind power generation apparatuses 10 and a plurality of the rotatingpedestals 50 supporting these wind power generation apparatuses 10 so asto be rotatable. In the aggregate, the anemovane 61 may be installed oneby one in the vicinity of the plurality of wind power generationapparatus 10, or may be installed in the vicinity of any one of the windpower generation apparatuses 10, and directly or indirectly transmit theinformation related to the measured wind direction and/or wind power(wind velocity) from the single anemovane 61 to each control device 55of the plurality of the rotating pedestal 50. Here, indirecttransmission of information means transmission of information to theother control device 55 through any one or more of the control devices55, for example.

FIG. 6 is a flowchart illustrating an example of a control process ofthe rotating pedestal according to an embodiment of the presentinvention. The sequence of processes composing the flowchart describedbelow is in random order in such a range that a contradiction or aninconsistency is not caused in process contents.

First, the anemovane 61 measures the wind direction and the wind powerin the vicinity of the wind power generation apparatus 10 (Step S1).Then the anemovane transmits measurement data related to the measuredwind direction and wind power to the control device 55 of the rotatingpedestal 50 (Step S2).

The control device 55 then receives the measurement data related to thewind direction and the wind power measured by the anemovane (Step S3).Next, the control device then controls the rotational angle and therotational speed of the rotating part 51 based on the measurement datareceived in Step S3. Specifically, first, it is determined whether ornot there is dislocation between the direction of the rotating part 51equivalent to the direction of the intake port of the wind powergeneration apparatus 10 (hereinafter also referred to as the “directionof the intake port”), and the wind direction indicated by themeasurement data (Step S4). In a case in which there is no dislocationbetween the direction of the intake port, and the wind directionindicated by the measurement data (NO in Step S4), the rotating pedestaldoes not need to be rotated, and therefore the process is terminated.The case in which there is no dislocation between the direction of theintake port, and the wind direction indicated by the measurement datameans a case in which dislocation between the direction of the intakeport of the wind power generation apparatus 10, and the direction fromwhich wind blows is, for example, within ±3 degrees.

In a case in which there is dislocation between the direction of theintake port, and the wind direction indicated by the measurement data(YES in Step S4), it is determined whether the wind power indicated bythe measurement data is a threshold value 1 or less, or a thresholdvalue 2 or more (Step S5).

Here, the threshold value 1 is, for example, a value that gives anexcessive burden on the wind power generation apparatus 10 due to toomuch wind power, or a value that is not suitable for rotation of therotating part 51 due to too much wind power. The threshold value 1 canbe appropriately set by the weight, the durability, and the like of thewind power generation apparatus 10, and preferably is, for example, windvelocity of 30 m/s, and more preferably is wind velocity of 20 m/s.

The threshold value 2 is, for example, a value that indicates such windpower as to destroy the wind power generation apparatus 10. Thethreshold value 2 can be appropriately set by the weight, thedurability, and the like of the wind power generation apparatus 10, andpreferably is, for example, wind velocity of 40 m/s, and more preferablyis wind velocity of 60 m/s.

In a case in which the wind power indicated by the measurement data islarger than the threshold value 1 and less than the threshold value 2(NO in Step S5), the rotating part 51 is not rotated, and the process isterminated. In this case, until the wind power becomes wind power (forexample, the threshold value 1 or less) suitable for rotation of therotating part 51, or, such wind power (for example, the threshold value2 or more) as to destroy the wind power generation apparatus 10, thedirection of the intake port is maintained to be the present direction.

In a case in which the wind power indicated by the measurement data isthe threshold value 1 or less (YES in Step S5), the rotational speed ofthe rotating part 51 is determined based on the wind power indicated bythe measurement data. For example, the weaker the wind power is, thefaster the rotational speed preferably becomes. In a case in which thewind power is weak, the direction of the intake port is directed in thedirection from which the wind blows, and the power generating efficiencyis more promptly improved. In a case in which the wind power is strong,the rotational speed is preferably made slow in order to reduce burdenson the wind power generation apparatus 10 and the rotating pedestal bywind, and reduce the rate of occurrence of failure.

In a case in which the wind power indicated by the measurement data isthe threshold value 2 or more (YES in Step S5), the direction of theintake port tries to be directed in the direction from which the windblows in order to prevent the wind power generation apparatus 10 frombeing destroyed by very strong lateral wind received by the wind powergeneration apparatus 10. The rotational speed at this time is preferablyslow compared to a case in which the wind power is the threshold value 1or less.

Next, the control device 55 rotates the rotating part 51 at therotational speed determined in Step S6 such that the direction of theintake port is directed in the direction from which wind blows, andterminates the process.

REFERENCE SIGNS LIST

-   10 WIND POWER GENERATION APPARATUS-   11 DUCT-   12 FRONT END (INTAKE PORT)-   13 MINIMUM INNER DIAMETER PART-   14 REAR END (EXHAUST PORT)-   15 CABLE HOLE-   16 WIND DIRECTION ADJUSTER-   17 SKIRT PART-   18 EDGE-   19 CENTRAL AXIS-   30 CYLINDRICAL CONTAINER-   31 IMPELLER-   32 BLADE-   33 ROTATING SHAFT-   34 POWER GENERATOR-   35 CURRENT COLLECTION CABLE-   40 SUPPORT-   41 SUPPORT PLATE-   42 LEG PART-   50 ROTATING PEDESTAL-   51 ROTATING PART-   52 FIXING PART-   53 CABLE HOLE-   54 BASE PART-   55 CONTROL DEVICE-   56 BALL BEARING-   61 ANEMOVANE-   62 CABLE

What is claimed is:
 1. A wind power generation system comprising: a windpower generation apparatus that includes at least: a duct having alongitudinal cross section formed in a substantial streamline shape, thelongitudinal cross section being taken along a central axis of the duct,an impeller placed in the duct, and a power generator that generatespower by rotation of the impeller; an anemovane installed and configuredto measure a wind direction and a wind velocity in a vicinity of thewind power generation apparatus; a rotating pedestal that supports thewind power generation apparatus so as to be rotatable along a supportingsurface; and a control device that controls a rotational angle of therotating pedestal based on the wind direction and/or the wind velocitymeasured by the anemovane, wherein the control device controls therotating pedestal to not rotate when the control device determines thatthe wind velocity measured by the anemovane is between a first thresholdvalue indicating a first value of excessive wind velocity and a secondthreshold value indicating a second value of excessive wind velocitythat is higher than the first value of excessive velocity, the firstvalue of excessive wind velocity indicates a wind velocity that gives anexcessive burden on the wind power generation apparatus, the secondvalue of excessive wind velocity indicates a wind velocity sufficient todestroy the wind power generation apparatus, and when the control devicedetermines that the wind velocity measured by the anemovane is equal toor less than the first threshold value, the control device furthercontrols a rotational speed of the rotating pedestal to increase whenthe wind velocity measured decreases and controls the rotational speedof the rotating pedestal to decrease when the wind velocity measuredincreases.
 2. The wind power generation system according to claim 1,wherein at least a portion of an inner wall of the duct narrows indiameter toward the central axis of the duct so that the duct includes aminimum inner diameter part at which an inner diameter of the duct isminimum, and the minimum inner diameter part is disposed between anintake port of the duct and an exhaust port of the duct.
 3. The windpower generation system according to claim 1, wherein the impeller isplaced between the minimum inner diameter part and the exhaust port ofthe duct, and a distance from the minimum inner diameter part to theimpeller is in a range of 19.8 to 29.0% of a distance from the minimuminner diameter part to the exhaust port.
 4. The wind power generationsystem according to claim 1, wherein a support for supporting theimpeller and the power generator is erected from an inner wall of theduct toward a center of gravity of the duct or a vicinity of the centerof gravity.
 5. The wind power generation system according to claim 1,wherein the impeller has four blades.
 6. The wind power generationsystem according to claim 1, wherein when the control device determinesthat the wind velocity measured by the anemovane is equal to or greaterthan the second threshold value, the control device further controls therotational speed of the rotating pedestal to be slower than therotational speed of the rotating pedestal used when the control devicedetermines that the wind velocity measured by the anemovane is equal toor less than the first threshold value.
 7. The wind power generationsystem according to claim 1, wherein when the control device determinesthat the wind velocity measured by the anemovane is equal to or greaterthan the second threshold value, the control device further controls therotational speed of the rotating pedestal based on the wind velocitymeasured by the anemovane.
 8. The wind power generation system accordingto claim 1, wherein an outer periphery of the duct includes a winddirection adjuster on a rear side of the duct, the wind directionadjuster being shaped from a skirt part and an edge, the skirt partbeing composed of an inclined plane formed so as to angle away from thecentral axis toward an exhaust port side of the duct, and the edge beingconnected to the skirt part and having a surface extending from theskirt part away from the central axis and being substantiallyperpendicular to the central axis.
 9. The wind power generation systemaccording to claim 1, wherein the first threshold value is 30 m/s, andthe second threshold value is 40 m/s.
 10. The wind power generationsystem according to claim 1, wherein the first threshold value is 20m/s, and the second threshold value is 60 m/s.
 11. A control method tobe executed in a wind power generation system, the wind power generationsystem comprising: a wind power generation apparatus that includes atleast: a duct having a longitudinal cross section formed in asubstantial streamline shape, the longitudinal cross section being takenalong a central axis of the duct, an impeller placed in the duct, and apower generator that generates power by rotation of the impeller; ananemovane installed and configured to measure a wind direction and awind velocity in a vicinity of the wind power generation apparatus; arotating pedestal that supports the wind power generation apparatus soas to be rotatable along a supporting surface; and a control device thatcontrols a rotational angle of the rotating pedestal based on the winddirection and/or the wind velocity measured by the anemovane; thecontrol method comprising: controlling the rotating pedestal to notrotate when the wind velocity measured is between a first thresholdvalue indicating a first value of excessive wind velocity and a secondthreshold value indicating a second value of excessive wind velocitythat is higher than the first value of excessive velocity; increasing arotational speed of the rotating pedestal when the wind velocitymeasured is equal to or less than the first threshold value and the windvelocity measured is decreasing; and decreasing the rotational speed ofthe rotating pedestal when the wind velocity measured is equal to orless than the first threshold value and the wind velocity measured isincreasing, wherein the first value of excessive wind velocity indicatesa wind velocity that gives an excessive burden on the wind powergeneration apparatus, and wherein the second value of excessive windvelocity indicates a wind velocity sufficient to destroy the wind powergeneration apparatus.